<div class="box box-primary" style="width:500px;margin:50px auto">
    <div class="box-header with-border">
        <h3 class="box-title">用户注册</h3>
    </div>
    <!-- /.box-header -->
    <!-- form start -->
    <form role="form">
        <div class="box-body">
            <div class="form-group">
                <label for="signup-username">用户名：</label>
                <input type="text" class="form-control" id="signup-username" placeholder="请输入用户名">
            </div>
            <div class="form-group">
                <label for="signup-password">密码</label>
                <input type="password" class="form-control" id="signup-password" placeholder="请输入密码">
            </div>
            <div class="form-group">
                <label for="exampleInputFile">头像</label>
                <input type="file" id="exampleInputFile">

                <p class="help-block">请选择一张图片作为你的头像</p>
            </div>
        </div>
        <!-- /.box-body -->

        <div class="box-footer">
            <button type="submit" class="btn btn-primary" id="user-signup">注册</button>
        </div>
    </form>
</div>